package com.jiukuaidao.library.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Util {
    /**
     * 默认的密码字符串组合，用来将字节转换成 16 进制表示的字符,apache校验下载的文件的正确性用的就是默认的这个组合
     */
    protected static char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};

    protected static MessageDigest messagedigest = null;

    static {
        try {
            messagedigest = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException nsaex) {
            nsaex.printStackTrace();
        }
    }

    /**
     * 生成字符串的md5校验值
     *
     * @param s
     * @return
     */
    public static String getMD5String(String s) {
        return getMD5String(s.getBytes());
    }

    /**
     * 判断字符串的md5校验码是否与一个已知的md5码相匹配
     *
     * @param password  要校验的字符串
     * @param md5PwdStr 已知的md5校验码
     * @return
     */
    public static boolean checkPassword(String password, String md5PwdStr) {
        String s = getMD5String(password);
        return s.equals(md5PwdStr);
    }

    /**
     * 生成文件的md5校验值
     *
     * @param file
     * @return
     * @throws IOException
     */
    public static String getFileMD5String(File file) throws IOException {
        InputStream fis;
        fis = new FileInputStream(file);
        byte[] buffer = new byte[1024];
        int numRead = 0;
        while ((numRead = fis.read(buffer)) > 0) {
            messagedigest.update(buffer, 0, numRead);
        }
        fis.close();
        return bufferToHex(messagedigest.digest());
    }

    /**
     * JDK1.4中不支持以MappedByteBuffer类型为参数update方法，并且网上有讨论要慎用MappedByteBuffer，
     * 原因是当使用 FileChannel.map 方法时，MappedByteBuffer 已经在系统内占用了一个句柄， 而使用
     * FileChannel.close 方法是无法释放这个句柄的，且FileChannel有没有提供类似 unmap 的方法，
     * 因此会出现无法删除文件的情况。
     * <p>
     * 不推荐使用
     *
     * @param file
     * @return
     * @throws IOException
     */
    public static String getFileMD5String_old(File file) throws IOException {
        FileInputStream in = new FileInputStream(file);
        FileChannel ch = in.getChannel();
        MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY, 0, file.length());
        messagedigest.update(byteBuffer);
        String bufferToHex = bufferToHex(messagedigest.digest());
        in.close();
        return bufferToHex;
    }

    public static String getMD5String(byte[] bytes) {
        messagedigest.update(bytes);
        return bufferToHex(messagedigest.digest());
    }

    private static String bufferToHex(byte bytes[]) {
        return bufferToHex(bytes, 0, bytes.length);
    }

    private static String bufferToHex(byte bytes[], int m, int n) {
        StringBuffer stringbuffer = new StringBuffer(2 * n);
        int k = m + n;
        for (int l = m; l < k; l++) {
            appendHexPair(bytes[l], stringbuffer);
        }
        return stringbuffer.toString();
    }

    private static void appendHexPair(byte bt, StringBuffer stringbuffer) {
        char c0 = hexDigits[(bt & 0xf0) >> 4];// 取字节中高 4 位的数字转换, >>>
        // 为逻辑右移，将符号位一起右移,此处未发现两种符号有何不同
        char c1 = hexDigits[bt & 0xf];// 取字节中低 4 位的数字转换
        stringbuffer.append(c0);
        stringbuffer.append(c1);
    }

    public static String getJywBy17stirng(String s17) {
        if (17 != s17.length()) {
            return "0";
        }
        String[] ID_ICCID_array = new String[17];
        for (int i = 0; i < s17.length(); i++) {
            ID_ICCID_array[i] = String.valueOf(s17.charAt(i));
        }
        ;
        int s = (Integer.parseInt(ID_ICCID_array[0]) + Integer.parseInt(ID_ICCID_array[10])) * 7 + (Integer.parseInt(ID_ICCID_array[1]) + Integer.parseInt(ID_ICCID_array[11])) * 9 + (Integer.parseInt(ID_ICCID_array[2]) + Integer.parseInt(ID_ICCID_array[12])) * 10 + (Integer.parseInt(ID_ICCID_array[3]) + Integer.parseInt(ID_ICCID_array[13])) * 5 + (Integer.parseInt(ID_ICCID_array[4]) + Integer.parseInt(ID_ICCID_array[14])) * 8 + (Integer.parseInt(ID_ICCID_array[5]) + Integer.parseInt(ID_ICCID_array[15])) * 4 + (Integer.parseInt(ID_ICCID_array[6]) + Integer.parseInt(ID_ICCID_array[16])) * 2 + Integer.parseInt(ID_ICCID_array[7]) * 1 + Integer.parseInt(ID_ICCID_array[8]) * 6 + Integer.parseInt(ID_ICCID_array[9]) * 3;
        int y = s % 11;
        String M = "F";
        String JYM = "10X98765432";
        M = JYM.substring(y, y + 1);
        return M;
    }

    public static void main(String[] args) throws IOException {
        // long begin = System.currentTimeMillis();
        // md5('123456')=>e10adc3949ba59abbe56e057f20f883e
        // md5('abcde')=>ab56b4d92b40713acc5af89985d4b786
        // md5('酒仙网')=>718eed67665a782267e710d9c428cbc6
        // File file = new File("C:/12345.txt");
        // String md5 = getFileMD5String(file);
        String y = getMD5String("123456789");
        System.out.println(y);
        System.out.println(y.equals("e10adc3949ba59abbe56e057f20f883e"));
        String y1 = getMD5String("abcde");
        System.out.println(y1.equals("ab56b4d92b40713acc5af89985d4b786"));
        String y2 = getMD5String("酒仙网");
        System.out.println(y2.equals("718eed67665a782267e710d9c428cbc6"));
        // String md5 = getMD5String("123456789123455677");

        // long end = System.currentTimeMillis();
        // System.out.println("md5:" + y + " time:" + ((end - begin) / 1000) +
        // "s");
    }

    public final static String getMd5AndCharset(String s, String charset) {
        char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
        try {
            byte[] strTemp = s.getBytes(charset);
            MessageDigest mdTemp = MessageDigest.getInstance("MD5");
            mdTemp.update(strTemp);
            byte[] md = mdTemp.digest();
            int j = md.length;
            char str[] = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++) {
                byte byte0 = md[i];
                str[k++] = hexDigits[byte0 >>> 4 & 0xf];
                str[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(str);
        } catch (Exception e) {
            return null;
        }
    }
}
